This disclosure relates to a quick connector couplings to releasably secure a rigid tube to a receiver body. More particularly, it relates to a quick connector coupling with a separate outer spacer to deliver axial forces on the seal member, due to fluid pressure, directly to the receiver body.
For low pressure applications, such as liquid fuel or fuel vapor, quick connectors are commonly employed. These connectors typically connect a hose to a rigid tube and have a body and internal components made of molded plastic. Such quick connectors are illustrated in U.S. Pat. Nos. 5,161,832; 5,324,082; 5,626,371; and 5,628,531.
Quick connectors employing molded components have evolved which are designed for higher pressure applications, such as power steering systems or brake systems. The quick connectors releasably secure a metal tube with an upset formed near its end to a system component made of metal. The system component includes a tube receiving port or bore shaped to coact with the connector components to releasably retain the tube in fluid tight relation to the bore in the system component. One such connector arrangement is illustrated in application for U.S. patent No. 11/218,666 filed Sep. 2, 2005, and published as No. 2006/0082149, Apr. 20, 2006, the disclosure of which, including specification, claims and drawings is incorporated herein by reference.
The connector components for high pressure applications (greater than 2,000 psi—actual system pressure) usually include a seal member in the form of an O-ring seal, a Teflon ring, an outer spacer and a retainer. The retainer includes a plurality of locking members having locking arms that releasably retain the metal tube in the bore of the system component. The quick connector retainer sustains the connection against the forces from application of fluid pressure on the end of the tube. The retainer locking members are designed with two separate pivot points to permit installation into the port of the system component, while already attached to the tube. The first pivot point, at the locking arms, allows the tube upset to pass beyond the locking arms and lock into the retainer. The second pivot point, at the column connection to the forward ring allows the retainer locking members to flex radially inward during tube assembly to the receiving bore in the system component. Two separate pivot points reduce the assembly force to acceptable levels.
The outer spacer is part of the “seal pack” which consists of a seal member such as an O-ring and one or more spacers that encompass the outside diameter of the mating tube positioned between the seal member and the outer spacer. The compression of the O-rings to the tube creates the seal while the outer spacer creates the shoulder of the gland area where the Teflon ring resides. The Teflon ring creates a compatible surface for the O-ring to abut as fluid pressure is applied. The outer spacer receives the axial load of the fluid pressure acting on the seal member.
The design requirements dictate that the quick connector outer spacer disclosed here for high pressure applications must withstand up to 5,000 pounds per square inch (psi) for power steering and brake applications. The outer spacer consists of four compressive members or legs that flex inward during assembly and snap back outward and rest within a shoulder machined into the system component body. The outer spacer sustains the assembly against axial load of fluid pressure on the O-ring. Keeping the two fluid pressure loads separate allows the quick connector to handle higher system pressures.
It has been found that installation of the preassembled tube, seal pack, outer spacer and retainer into the bore of the system component may encounter excessive axial loading. Application of an axial force is necessary to cause the compressive members of the outer spacer and the locking members of the tube retainer to pass forwardly into the receiving bore. The excess loading characteristic results from the contact of the rearward ends of the outer spacer legs with the forward face of the ring of the retainer. The present invention eliminates this relationship and provides for application of axial insertion forces independently of the outer spacer legs.
The outer spacer four compressive members or legs are symmetrical and therefore the force generated by the fluid pressure will be distributed evenly which maximizes burst performance. The arrangement of the present invention also provides for stability of the outer spacer relative to the inserted tube, even in environment of high pressure pulsation or vibration. The extended cylindrical feature of the seal member retainer contains a bore which encircles the tube and minimizes effects of vibration of tube on the seal pack. This new arrangement is designed to keep the seal pack in position even after many cycles of temperature and vibration.